diff --git a/sfm/server.py b/sfm/server.py
index 09a43d0..eafdefd 100644
--- a/sfm/server.py
+++ b/sfm/server.py
@@ -323,6 +323,20 @@ def device_events(
             if ev.sample_rate is None:
                 ev.sample_rate = info.compliance_config.sample_rate
 
+    # Backfill event.project_info fields that the 210-byte waveform record doesn't carry.
+    # The waveform record only stores "Project:" — client/operator/sensor_location/notes
+    # live in the SUB 1A compliance config, not in the per-event record.
+    if info.compliance_config:
+        cc = info.compliance_config
+        for ev in events:
+            if ev.project_info is None:
+                ev.project_info = ProjectInfo()
+            pi = ev.project_info
+            if pi.client          is None: pi.client          = cc.client
+            if pi.operator        is None: pi.operator        = cc.operator
+            if pi.sensor_location is None: pi.sensor_location = cc.sensor_location
+            if pi.notes           is None: pi.notes           = cc.notes
+
     return {
         "device":      _serialise_device_info(info),
         "event_count": len(events),